To answer your question, yes that is what ketosis is. Eliminate the non-fibrous carbs from your diet and after 48 hours or once the carbs are out of your blood stream your body will start to break down stored body fat. Through a process in the liver you get ketones. In the context of meal planning, meal timing, and other lifestyle choices it's extremely effective. For anyone with ADHD / ADD patterns do TRY IT for a month!
The study and the discussion here however are focused on reducing the quantity of those adipocyte cells in the body, which aren't reduced through ketosis. I think ketosis causes more of a volumetric reduction of each adipocyte cell but I'm really not sure.
Like a balloon filling with air, do adipocyte cells expand in volume while storing lipids?
It is. But it's hard to maintain. I was in ketosis for a month via diet (verified with urine strips twice a day) and it was a struggle to figure out what to eat. Camembert, bacon-wrapped chicken and eggs gets boring after a while. Our civilization runs on carbohydrates, for better or worse.
Isn't ketosis the state, in which the body switches to fat as the primary fuel?